PostgreSQL

Create user for DB

// create user shota with password 1111, when logged in certain DB
CREATE USER shota WITH SUPERUSER LOGIN PASSWORD '1111';

// grant all privileges to specific user 
grant all privileges on database db_name to someuser;

Default users and passwords

Default postgres user:
username: postgres
password: postgres

Insert

// Insert data with primary + serial key
INSERT INTO press(
            id, sort_id, logo, description, link, link_text)
    VALUES (default, 3, 'fodors.png', 'Travel Trend: Eat Like Locals, With Locals.', 'http://www.fodors.com/', 'Fodors');

List DB or Tables

// list databases
\l

// list tables
\d

// list specific table content
\d tablename

// list roles
\du

// list commands
\help

// select all the data from table, IMPORTANT: dont forget semicolon
SELECT * FROM articles;

PostgreSQL core configuration

nano /var/lib/pgsql/data/pg_hba.conf

postgresql services

// start postgres service
sudo systemctl start postgresql.service

// view postgres service status
systemctl status postgresql.service

start PostgreSQL

// login to postgres database server 
su - postgres

// create db posttestdb under the owner of shota
createdb -O shota posttestdb

// Create DB called testDB
createdb testDB

// login to testDB database
psql testDB

User configuration

// make user SUPERUSER
ALTER ROLE <user_name> SUPERUSER;

// allow user create DB
ALTER ROLE clikhome CREATEDB;

// Other options
SUPERUSER
NOSUPERUSER
CREATEDB
NOCREATEDB
CREATEROLE
NOCREATEROLE
CREATEUSER
NOCREATEUSER
INHERIT
NOINHERIT
LOGIN
NOLOGIN
REPLICATION
NOREPLICATION
CONNECTION LIMIT connlimit
PASSWORD password
ENCRYPTED
UNENCRYPTED
VALID UNTIL 'timestamp'